The present invention relates to a seat used as, for example, a seat of a car.
In a seat used for a seat of a car and the like, in order to support the waist of a person who sits on the seat, bulging portions to bulge out forward are provided in the width direction on both sides of a seat back to form a recess in the center thereof, and a lumbar supporting portion is also provided which juts out around the lower portion of the recess slightly in front. The provision of these bulging portions and lumbar supporting portion enables the body on the seat to be held securely, to support the haunches and waist of a person sitting on the seat to prevent from leaning and shifting of the body during driving, and to prevent generation of an oppressive feeling of the abdomen and generation of a backache.
However, the waist-support by a conventional seat depends largely on the shape and size of a seat back as described above, and it is not possible to exhibit an appropriate waist-supporting function in response to difference in the physique. Accordingly, there may be cases where the waist-supporting function of a seat is not sufficient for a certain difference in the physique. There are some seats of which waist-supporting forces are made adjustable by supplying or exhausting air, but they have complicated structures and are expensive.
In a seat for plural persons, places corresponding to the positions between sitting persons are formed to bulge out in front for the seat back, and bulge out upward for a seat cushion. For this purpose, frame members are disposed on these border places between sitting persons in the back side of cushion members. The provision of the bulging portions has an advantage that a portion from the haunches to the waist can be held securely for any persons sitting on the seat, preventing from leaning and shifting of the body during driving, thereby preventing generation of a backache. However, it has a complicated structure and too much weight, which leads to a cost increase.
In order to make a baggage space in a car wider, a folding seat which has a structure of putting a seat back on a seat cushion in layer by pushing down the seat back in front has been known. However, if such a folding seat has a seat back structure provided with the above-described bulging portions, the total thickness of the seat back and the seat cushion when being folded is large so that the seat occupies too much space in the baggage space. In a seat for plural persons, since border frames are provided on the portions corresponding to the places between respective sitting persons as described above, if the seat is required to be a folding seat, the structure becomes much more complicated.
The present invention is carried out in view of the above-described circumstances, and its object is to provide a seat which enables to exhibit a waist-supporting function in response to difference in the physique, to improve the feeling of seating, and to manufacture it with a simple structure and at low cost.
Another object of the present invention is to provide a seat for a plural persons, which does not require to dispose a frame on a portion corresponding to a place between each sitting person, exhibits a waist-supporting function in response to difference in the physique to improve the feeling of seating, and enables to manufacture at low cost.
Still another object of the present invention is to provide a seat which has a structure capable of exhibiting the waist-supporting function in response to difference in the physique, but still enables to make the total thickness of the seat cushion and the seat back in a folded state thinner than the conventional folding seat so that its baggage space can be widened, and to which the present invention is applicable even for plural persons with a simple structure.
In accordance with one aspect of the present invention, a seat comprising: a seat cushion having a cushioning member supported by a seat frame; a seat back having a cushioning member supported by a back frame; and a belt member provided in the back side of each cushioning member, the belt member being held on an appropriate portion of the back frame at one end thereof and on an appropriate portion of the seat frame at the other end, disposed in the vicinity of, at least, either right or left side of a sitting person in a direction along the longitudinal cross-section, being designed to have the length in the overlapping area with the above-described cushioning members shorter than the length along an expanded state of the cushioning members in the same area and being designed to be made of a material having a higher stiffness than those of respective cushioning members.
A preferred embodiment of the present invention provides a seat in which one end of the belt member is held by engaging with an upper end frame of the back frame and the other end of the belt member is held by engaging with a front end frame of the seat frame.
A preferred embodiment of the present invention provides a seat in which a covering member is fixed on the back face of each cushioning member to form a substantially cylindrical shape with the back face, and the belt member is inserted in a hollow portion formed by the covering member.
A preferred embodiment of the present invention provides a folding seat in which each cushioning member is made of a net member in a three-dimensional structure in which a front mesh layer and a back mesh layer are connected with a large number of piles.
A preferred embodiment of the present invention provides a seat in which each cushioning member made of the net member in a three-dimensional structure has a one-piece structure united integrally with two cushioning members.
A preferred embodiment of the present invention provides a seat in which the belt members are disposed in the vicinity of both right and left sides of a sitting person.
A preferred embodiment of the present invention provides a seat in which the seat cushion and seat back are formed for plural persons, and the belt member is provided on a portion corresponding to a place between sitting persons.
A preferred embodiment of the present invention provides a seat in which the belt member has a restoration property.
A preferred embodiment of the present invention provides a seat in which a distance between the inner sides of the respective side frames composing the seat frame is arranged to be wider than a distance between the outer sides of the respective side frames composing the back frame,
and when the seat is folded, it can be folded in a manner that the respective side frames of the back frame are surrounded by the respective side frames of the seat frame so that the respective side frames of the back frame are positioned in the inside of the respective side frames of the seat frame.